php格式化日期实例分析

function ShowDate($flag=0,$timestr=NULL)?
{?
??? // 获取周几?
??? $warr = array(?
??? "0" => 星期日,?
??? "1" => 星期一,?
??? "2" => 星期二,?
??? "3" => 星期三,?
??? "4" => 星期四,?
??? "5" => 星期五,?
??? "6" => 星期六?
??? );?
??? $i = date("w",$timeStamp);?
???????
??? // 设置北京时间并获取时间戳?
??? date_default_timezone_set('PRC');?
??? $timeStamp = NULL;?
??? if ($timestr)?
??????? $timeStamp = strtotime($timestr);?
??? else
??????? $timeStamp = time();?
???
??? // 设置时间显示格式?
??? $ret1 = date("Y年m月d日 H:m:s",$timeStamp) . " " . $warr[$i];?
??? $ret2 = date("Y-m-d H:m:s",$timeStamp) . " " . $warr[$i];?
??? $ret3 = date("y/m/d",$timeStamp);?
??? $ret = $ret1; // 默认返回第一种?
???????
??? if ($flag == 2)?
??????? $ret = $ret2;?
??? else if ($flag == 3)?
??????? $ret = $ret3;?
???????????
??? return $ret;?
}